Arrangement for identifying calling lines



Sept. 30, 1958 A. HEETMAN ARRANGEMENT FOR IDENTIFYING CALLING LINES Filed March 13, 1956 INVENTOR ALPHONSUS HEETMAN BY%%%y/( AGENT United tates Patent .ARRANGEMENT FOR IDENTIFYINGCALLING LINES Alphonsus Heetrnan, Hilversum, Netherlands, assignor, by

:mesne assignments, to North American Philips Com- -pany,'lnc., New York, N. Y., a corporation of Delaware Application March 13, 1956, Serial No. 571,303

Claims-priority, application Netherlands March.2i8,;1955

2 Claims. (Cl. 179-1 8) .This inventionrelates to arrangements'for automatic signalling systems, more particularly telephone systems, for identifying a calling line of a group of lines each having associated with it, according to a matrix, a first digit and a second digit, for examplea tens digit-and a units digit.

The object of the invention is to provide a simple arrangement by which a line may immediately-be identified when a call is made. Such. an arrangement is more particularly important in telephone systems comprising cross-bar switches.

.In the arrangement according to the invention, each line has individually associated with it a magnetic-ally presaturated core, and a direct current flows through a first winding on the core upon calling. Furthermore, provision is made of a multiphase pulse generator periodically supplying pulses vshifted in time :to "a plurality of outlets each connected to -a secondwinding .on each of .the cores of lines corresponding to the same first digit.

Provision is also .made of a'first set of pulse receivers each coupled via an identifying wire to a third-winding on each of the cores of lines correspondingto'the same second digitand a second set of pulsereceivers which by means of the time-shifted pulses .from the-pulse generator are successively brought into-a condition. inwhich they .can respondwhen a pulse isreceived via one ofthe identifying wires. When a pulse'receiver of'the firstset and of the second set is responsive, the otherpulseireceivers are made insensitive to further pulses.

In order that the invention may be readily carried into efiect, one embodiment will now be described, by way of example, withreference to'the accompanying drawing.

The figure-shows a telephone set of-a subscriber AB, which is connected via line wires S1 and S2 to line :contacts a andb of a group of line finders OZ. 'The 'line wire S1 is connected via a resistor R1 to the negative terminal of a battery (not shown), the positive terminal of which is connected to earth. The line wire S2 is connected via a resistor S2 to the c-test contact of the line finders OZ and to one end of a winding LA 21 on a magnetic core M21 individually associated with the line. The other end of the winding LA21 is connected to earth via a resistor R21. The subscriber AB forms part of a group of, say, 100 subscribers or more, the subscribers in the latter case being distributed over a plurality of groups of line finders. The subscribers sets are distinguished from one another by two digits, for example in the case of 100 subscribers per group by the tens digit and the units digit of the subscribers number, or in the case of a system having cross-bar switches by the digit of the switch and its position on the switch. The two last digits of the subscribers number of the telephone set shown are, for example, equal to 21. The other subscribers sets of the group are coupled in a similar manner to other magnetic cores which are ranged in the figure according to a matrix MS in such manner that the sets having the same tens digit are coupled to the 2,854,517 Patented Sept. 30,, 1:953

"ice

2 cores of the same vertical column of the matrix, for example the cores M11, M12 Mln for the sets, 10f

which the tens digit is 1, or coupled to the-cores M21, M22 M2n for the sets, of which the .tens digit :15 equal to 2. The sets having the same units digit are coupled to the cores of the same horizontal row of the matrix MS, for example thesets of which the units digit is equal to 1 are coupled to the cores MlLI'M'Zl Mnl, and the sets of which vthe units digit is equal .10 2 are coupled to the "cores,M12, M22 M2n. The vcoresof .the same horizontal row of the 'matrixMS are coupled by means of a :second windingpand one of the identifying wires D1, D2 Dn to a winding on one of the auxiliary cores MEI, ME2 IMEn. Thus, for example, the cores M11, M21 Mmlarescouple'd by means of windings LD11, :LD21 ..LDm1;and the identifying wire D1 to the windingLDl on .the core MEI. The cores M12, M22 Mm2 are coupled in a similar manner-via wire D2 to the winding LD2 :on the core ME2. The cores of the same vertical column 0f .the matrix MS simultaneously receive a pulse from a multiphase .pulse generator MP. The pulse generator MP is of a designsuch that it periodically supplies pulses .shifted in time to its outlets U1, U2 Um, which are connected to a third Winding:.011 the coreof the same verticalcolumn of the matrix MS. Thus, .'-for .ex-

ample, :the outlet U2 is coupled via capacitor C2 and a pulse wire V2 to the windingsLVZl, LV22, LV2n .on the .coresM21, M22 M2n. Howeventhexpulses are normally not transferredto .theidentifying .wires D1, D2, Dn,,.the:cores normally .bcing magneticallyzpre- :saturatedas a; result ofthe direct-current flowing (through the thirdwinding. Thus, for -example,:the:..cores M21, M22 M2n are magnetically .presaturated by :Lthe..direct cur-rent Eflowin-g, through the circuit :comprising a resistor .RV2, the wire Y2 and the windings LVZn LV22 andILVZl.

;However,if one :ofthe subscribers, for example subscriber 21, is calling, a circuit'is :established from the negative terminal of :the battery -via resistor R1, :line wire .81, telephone set of subscriber AB (21), line wire S2,. resistor, R2, winding LA21 and-resistor R2110 earth. As :a-resultiof the direct current flowing through said circuit :via winding LA21, the magnetic condition -of'the core M21 is varied in such manner 'that'the pulsesare nowztransferred from the winding LV2-1 to the winding LD21and the identifying wire D1. The auxiliar-ycore MEI: transfers the pulses :from the winding LDI via the windingiL-El to the identifying wire E1, and via the winding ELTl, the windings LT2, .llTn on the auxiliary cores ME2 MEn and the Wire 0G to a calling detector OD. The calling detector OD, which may be of a construction known per se, responds thereto and connects via contacts odl, 0d2, odn an identifiying device IR, which, for example, may form part of a register circuit, to identifying wires E1, E2 En. The identifying device IR comprises two sets of pulse receivers, the first set comprising gas filled tubes GEl, GE2, GEn and the second set comprising gas-filled tubes GT1, GT2 GTn. The first group of the pulse receivers serves to identify the identification wires through which the pulses are supplied, in other words of the second digit associated with the calling line, that is to say the units digit, the other group of pulse receivers serving to determine the moment, at which the pulses are received, in other words to identify the first digit associated with the calling line, that is to say the tens digit.

The cathodes of the gas-filled tubes GEl, GE2 GEn are connected to earth via a common resistor RKE, their anodes being connected via a winding on relays DEl, DE2 DB1: and back contact cs of a relay (not shown) to a voltage source of about 160 volts which is likewise not shown. The ignition electrodes of said tubes are connected on the one hand, via resistors REl, RE2 REn to a source having a voltage a little lower than the ignition voltage and, on the other hand, via capacitors CB1, CE2 CEn and contacts odl, odZ, odn to the identifying wires E1, E2, As a result of the pulses supplied via wire E1 when subscriber AB (21) is calling, the potential of the ignition electrode of gas-filled tube GEl exceeds the striking voltage and the tube becomes conducting, so that relay DEl is magnetised. As a result of the voltage drop across resistor RKE, the potential of the cathodes of the tubes of the group concerned increases to a value such that thereafter none of the other tubes can be ignited if a pulse were to be supplied through one of the identifying wires E2, etc. The units digit of the calling subscriber is thus identified.

The cathodes of the gas-filled tubes GT1, GT2 GTm are connected to earth in a similar manner via a common resistor RKT, their anode circuit including the windings of relays DT1, DT2 DTm. The ignition electrodes of said tubes are connected via resistors RTl,

RT2 RTm to the outlets U1, U2 Um of pulse generator MP. The ignition electrodes are also coupled via capacitors CTl, CT2 CTm to the cathodes of tubes GEl, GE2 GEn. The ignition electrodes thus receive in succession an increased biassing potential, so that as a result of the pulse supplied via the capacitors CT1, CT2, etc. to the ignition electrodes of the tubes GT1, GT2 etc. when the potential of the cathode of the tubes GEl, GE2, etc. increases, one of the tubes CTl, CT2 is ignited and the associated relay energized. In the case under consideration, the gas-filled tube GT1 becomes conducting, since at the moment, at which the pulse is received via wire E1, the ignition electrode of this tube still has a comparatively high biassing potential whereas that of the other gas-filled tubes of this group is still comparatively low. It is to be noted in this connection that at the beginning of a pulse across an outlet of the pulse generator MP, the voltage of the ignition electrode connected to this outlet-is still comparatively low, since it takes some time before the associated capacitor CT1, etc. has been charged. The pulse which occurs across the wire E1 when subscriber AB (21) is calling occurs, however, at the beginning of the pulse across outlet U2 due to the difierentiating action of capacitor C2, this is to say at the moment, at which the ignition electrode of gas-filled tube GT1 still has a comparatively high biassing potential by the action of the pulse across the outlet U1, since it takes some time before capacitor CT1 has discharged. In connection therewith, the identifying digit 2 is assigned to the relay DT1, the identifying digit 3 is assigned to the relay DT2, and

4 the identifying digit 1 is assigned to the relay DTn. Due to the voltage drop across resistor RKT, the potential of the cathodes of the gas-filled tubes GT1, GT2, etc. increases to a value such that none of the other tubes can be ignited, the subscriber concerned thus being identified. After the subscriber has been found by a line finder OZ in a manner which is not shown, the c wiper of this line finder is connected via contact ca to earth,

' so that the direct current traversing the winding LA (21) disappears and the core M21 returns to its initial magnetically presaturated condition. The identifying arrangement IR is restored to a condition for identifying a subsequent calling line due to contact cs being opened for a short time by means (not shown), as a result of which the gas-filled tubes DB1 and DT1 are extinguished.

What is claimed is:

1. An automatic signalling system for identifying a calling line of a group of lines which have associated therewith a first digit and a second digit arranged according to a matrix, comprising a plurality of magnetically presaturated across associated with said lines in a matrix manner, each of said cores having a first, a second and a third winding associated therewith, means responsive to a call on a line for causing a current to How in the first winding of the core associated with the calling line, a multiphase pulse generator for periodically supplying pulses shifted in time to the second windings of said cores which are associated with lines having the same first digit, a first set of pulse receivers, identification wire means coupling said pulse receivers to the third windings of said cores which are associated with lines having the same second digit, a second set of pulse receivers connected to be brought successively into responsive condition by said time-shifted pulses, means connected to enable said second set of pulse receivers to respond when a pulse occurs on one of said identification wire means, and means connected to prevent the remainder of said pulse receivers from responding to a pulse when one of said pulse receivers is in a responsive condition.

2. A system as claimed in claim 1, in which each of said sets of pulse receivers comprises a plurality of gasfilled devices each having a pair of discharge electrodes, and in which said last-named means comprises a resistor in each set of receivers connected in common to a dis: charge electrode of all of said gas-filled devices of the respective set of receivers.

References Cited in the file of this patent UNITED STATES PATENTS 2,351,551 ;Seibel June 13. 1944 2,604,540 Blake July 22, 1952 2,694,753 Den Hertog Nov. 16, 1954 UNITED STATES PATENT OFFICE CERTIFICATE OF (10 EQTEON Patent No, 2,85%517 September 30, 1958 Alphoneus Heetman It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 21, for "preeaturated across" read m preeaturated Signed and sealed this 6th day of January 1959&

SEAL uest: V

KARL AXLINE ROBERT C. WATSON Commissioner of Patents Attesting Ofiicer 

